Inductors are important elements of many electronic devices. Inductors may also be implemented in integrated circuits, such as within an oscillator of an integrated circuit. However, as the density of integrated circuits continue to increase, noise may affect certain circuits of the integrated circuit. An inductor may be one element of an integrated circuit that may be affected by noise, and require shielding to improve the quality factor, or Q-factor, of the integrated circuit.
In general, a pattern ground shield (PGS) metal associated with a spiral inductor enables shielding and picking up the substrate noise, as well as enhancing Q-factor of a spiral inductor. Theoretically, if the PGS can be transparent to spiral inductor's H-field and block the spiral inductor's E-field from penetrating into the electrically lossy substrate without introducing any conduction current, then the Q-factor of a spiral inductor can be improved. As the integrated circuit industry moves to 7 nanometer (nm) transistor channel length dimensions and below, unidirectional metal and metal mask coloring may be required, making the implementation of a PGS in an integrated circuit device complex.
Accordingly, circuits and methods of implementing an inductor in an integrated circuit are desired.